Implantable prosthesis for soft tissue repair

ABSTRACT

An implantable prosthesis for mending anatomical defects, including a groin hernia. The prosthesis includes a prosthetic repair patch that may be implanted in different tissue planes to mend a defect. The patch may include a medial portion configured to be positioned in a first tissue plane and a lateral portion configured to be positioned in a second tissue plane offset from the first tissue plane. The patch may include a transition region configured to extend through tissue and/or muscle, such as fascia, separating the tissue planes and transition the patch from one tissue plane to the other tissue plane. The transition region may be configured to inhibit buckling and/or bunching of the patch when implanted through the fascia. The lateral portion of the patch may have a level of stiffness that facilitates implantation of the patch in different tissue planes while inhibiting patient sensation to the implanted patch.

FIELD

The present invention relates to an implantable prosthesis, and moreparticularly, to a prosthesis for mending a defect in a soft tissue ormuscle wall.

BACKGROUND

Groin hernias are typically characterized as indirect inguinal hernias,direct inguinal hernias, and femoral hernias. It is known to repair suchhernias by covering the defect with a prosthetic repair patch. In theclassic ‘Lichtenstein’ procedure, the patch is placed anteriorly of thetransversalis fascia. Alternatively, the patch may be positionedposteriorly of the transversalis fascia, for example, in thepreperitoneal space between the transversalis fascia and the peritoneum.

A prosthetic repair patch may be delivered laparoscopically to thepreperitoneal space in a procedure known as TEP—“Totally ExtraPeritoneal”. Alternatively, a prosthetic repair patch may be placed inthe preperitoneal space via an ‘open’ procedure.

Two common open procedures for preperitoneal placement of a prostheticrepair patch include the POLYSOFT Hernia Patch procedure and the Kugelprocedure. In the POLYSOFT approach, access to the preperitoneal spaceis through the defect itself. In the Kugel procedure, an opening isformed directly through the three layers overlying the preperitonealspace—the external oblique aponeurosis, the internal obliqueaponeurosis, and the transversalis fascia. In both the POLYSOFTprocedure and the Kugel procedure, the prosthetic repair patch ispositioned in a single tissue plane between the peritoneum and thetransversalis fascia.

Another open procedure for mending a groin hernia is the ONSTEPprocedure which involves placement of a prosthetic repair patch in twodifferent tissue planes. A medial portion of the patch is placed in thepreperitoneal space and a lateral portion of the patch is placed in atissue plane anteriorly of the transversalis fascia with a segment ofthe patch extending through the transversalis fascia.

It is an object of the present invention to provide a prosthesis formending defects in soft tissue and muscle walls.

SUMMARY OF INVENTION

The present invention relates to an implantable prosthesis for mendingan anatomical defect, such as a tissue or muscle wall defect, includinga groin defect.

In one embodiment, an implantable prosthesis is provided for mending agroin hernia. The implantable prosthesis comprises a patch of repairfabric including a medial portion, a lateral portion and a transitionregion, and a support member located along the medial portion, thelateral portion and the transition region to help deploy and/or hold thepatch in a spread out configuration. The medial portion is configured tobe positioned at a first tissue plane, the lateral portion is configuredto be positioned at a second tissue plane offset from the first tissueplane, and the transition region is configured to be positioned throughtissue and/or muscle separating the first and second tissue planes. Thesupport member includes a transition segment associated with thetransition region of the patch. The transition segment is located fromat least 2.5 cm to at least 5.1 cm from the lateral end of the patch andhas an outer width that does not exceed 4.2 cm.

In another embodiment, an implantable prosthesis is provided for mendinga groin hernia. The implantable prosthesis comprises a patch of repairfabric including a medial portion and a lateral portion. The medialportion is configured to be positioned at a first tissue plane, and thelateral portion is configured to be positioned at a second tissue planeoffset from the first tissue plane and separated by tissue and/ormuscle. The lateral portion has a stiffness of 0.04 psi to 0.09 psi.

In a further embodiment, a method is provided for mending a groinhernia. The method comprising acts of providing an implantableprosthesis and implanting the prosthesis to mend the groin hernia. Theprosthesis includes a patch of repair fabric and a support member tohelp deploy and/or hold the patch in a spread out configuration. Thepatch includes a medial portion, a lateral portion and a transitionregion, and the support member is located along the medial portion, thelateral portion and the transition region. The support member includes atransition segment associated with the transition region. The prosthesisis implanted by positioning the medial portion of the patch at a firsttissue plane, positioning the lateral portion of the patch at a secondtissue plane offset from the first tissue plane, and positioning thetransition region of the patch through an opening in tissue and/ormuscle separating the first and second tissue planes. The transitionsegment of the support member has an outer width that does not exceed acorresponding dimension of the opening.

The foregoing is a non-limiting summary of the invention, which isdefined by the attached claims. Other aspects, embodiments and/orfeatures will become apparent from the following description.

BRIEF DESCRIPTION OF DRAWINGS

Various embodiments of the invention will now be described, by way ofexample, with reference to the accompanying drawings, in which:

FIG. 1 is a plan view of an implantable prosthesis for mending ananatomical defect according to one illustrative embodiment;

FIG. 2 is an exploded perspective view of the implantable prosthesis ofFIG. 1;

FIG. 3 is a plan view of an implantable prosthesis for soft tissuerepair according to another illustrative embodiment;

FIG. 4 is an exploded perspective view of the implantable prosthesis ofFIG. 3;

FIG. 5 is a schematic illustration of the prosthesis of FIGS. 1-2 beingimplanted to mend a groin hernia; and

FIG. 6 is a schematic illustration of a test fixture for testing thestiffness of a portion of an implantable prosthesis.

DETAILED DESCRIPTION

It should be understood that aspects of the invention are describedherein with reference to the figures, which show illustrativeembodiments in accordance with aspects of the invention. Theillustrative embodiments described herein are not necessarily intendedto show all aspects of the invention, but rather are used to describe afew illustrative embodiments. Thus, aspects of the invention are notintended to be construed narrowly in view of the illustrativeembodiments. It should be appreciated, then, that the various conceptsand embodiments discussed herein may be implemented in any of numerousways, as the disclosed concepts and embodiments are not limited to anyparticular manner of implementation. In addition, it should beunderstood that aspects of the invention may be used alone or in anysuitable combination with other aspects of the invention.

The invention is directed to an implantable prosthesis for mending ananatomical defect, and is particularly suitable for mending defects in,and weaknesses of, soft tissue and muscle walls or other anatomicalregions. The phrase “mending a defect” includes acts of repairing,augmenting, and/or reconstructing a defect and/or a potential defect.For ease of understanding, and without limiting the scope of theinvention, the prosthesis is described below particularly in connectionwith mending a groin defect including, but not limited to, one or moreof an indirect inguinal hernia, a direct inguinal hernia, a femoralhernia and/or other weakness or rupture of the groin anatomy. It shouldbe understood, however, that the prosthesis is not so limited and may beemployed in other anatomical procedures, as should be apparent to one ofskill in the art.

The invention is more particularly directed to a prosthesis, such as aprosthetic repair patch, that may be implanted in different tissueplanes to mend a defect. The patch may include a repair fabric having abody portion that is configured to be positioned in at least two offsettissue planes. For example, and without limitation, the patch mayinclude a medial portion that is configured to be positioned in a firsttissue plane and a lateral portion that is configured to be positionedin a second tissue plane that is offset from the first tissue plane. Thepatch may also include a transition region that is configured to extendthrough tissue and/or muscle separating the tissue planes and transitionthe patch from one tissue plane to the other tissue plane. Thetransition region may extend along and be part of the lateral portionand/or the medial portion, although the transition region may be adistinct portion of the patch located between the lateral and medialportions. Upon implantation of the patch, a segment of the patchassociated with the transition region is to be positioned within thetissue and/or muscle. The specific segment will depend on the positionof the implanted patch within the anatomy.

In one embodiment, the prosthesis may be configured to mend a groinhernia, including direct and indirect hernias. For such a repair, themedial portion may be configured for placement in a preperitoneal space,such as the space of Retzius. The lateral portion may be configured forplacement in a separate tissue plane, such as anteriorly of thetransversalis fascia, in an onlay position. The transition region may beconfigured to extend from the lateral portion along the spermatic cordand through the transversalis fascia to the medial portion with asegment of transition region being located within the thickness of thetransversalis fascia. The prosthesis may be particularly configured formending a groin hernia using the ONSTEP procedure

The transition region may be configured to inhibit buckling and/orbunching of the patch that could otherwise potentially occur due toplacement of the transition region through the transversalis fascia. Forexample, the transition region may be configured to inhibit squeezing orpinching by the transversalis fascia and/or other anatomical features toan extent that could otherwise cause the patch material to buckle and/orbunch. For purposes of this application, the term “inhibit” includesrestrain, reduce, limit, minimize, avoid and/or prevent.

The patch may be configured to have sufficient stiffness or rigidity sothat it can be easily and effectively manipulated and positioned in adesired anatomical region, yet have sufficient flexibility or complianceso that the patch may be adequately handled by the physician implantingthe patch. The balance of stiffness and flexibility may facilitatedeployment and implantation of portions of the patch in different tissueplanes while inhibiting one or more undesirable consequences that couldpotentially occur from implantation of the patch. For example, andwithout limitation, the patch may be configured to inhibit patientsensation such that the implanted patch may be tolerated by the patient.In one embodiment, the lateral portion of the patch may be configuredwith a level of stiffness that facilitates implantation of the patch indifferent tissue planes while inhibiting patient sensation to theimplanted patch.

The prosthesis may include a member, such as a support member, that maybe arranged in or on the repair fabric. The support member may provide adesired level of stiffness or rigidity that helps deploy and/or hold thebody portion in an open or spread out configuration for mending thedefect. The support member may also provide a desired level ofresiliency or compliance that facilitates manipulating the body portionand allows the support member to deform from an initial shape and thenreturn to the initial shape to return the body portion of the patch tothe spread out configuration. The support member, alone or together withthe repair fabric, may also provide a desired level of flexibility orcompliance that permits the prosthesis to be flexed and implanted indifferent tissue planes while inhibiting patient sensation from theimplanted prosthesis.

The support member may be configured to extend along the medial portion,the transition region and the lateral portion. One or more segments ofthe support member extending along the transition region may beconfigured to inhibit being squeezed or pinched when positioned throughtissue and/or muscle, such as the transversalis fascia, separatingtissue planes so as to inhibit buckling or bunching the implanted patch.In one embodiment, the portion of the support member extending along thetransition region may have an outer width that does not exceed the sizeof the incision, dissection or other opening created through the tissueand/or muscle. A portion of the support member extending along themedial portion of the patch may be wider than the portion of the supportmember along the transition region and larger than the size of theopening through the tissue and/or muscle. A portion of the supportmember extending along the lateral portion of the patch may be narrowerthan along the transition region.

The support member may be configured to substantially surround the bodyportion, such as in a ring-like manner, to help deploy and/or hold thebody portion in an open or spread out configuration. The support membermay be configured to generally follow the shape of the outer peripheryof the repair fabric about the body portion. One or more segments of thesupport member may deviate inwardly away from the outer periphery towardthe body portion to inhibit contact with adjacent anatomical featuresthat may be present during a repair procedure. The inwardly directedsegments of the support member may form one or more indentations ornotches. A portion of the repair fabric may extend across eachindentation or notch between the support member and the outer periphery.Alternatively, the prosthesis may be configured with the outer peripheryof the repair fabric following the shape of the support member so thateach indentation or notch is substantially free of repair fabricmaterial.

The support member may include a pair of indentations or notches toaccommodate a particular repair procedure and/or anatomical feature atthe repair site. For example, and without limitation, the indentationsmay be located along the transition region of the repair fabric to format least a portion of a transition segment of the support member with areduced outer width for placement through tissue and/or muscleseparating tissue planes. This configuration may inhibit inwardlydirected radial forces being exerted against the support member byadjacent tissue and/or muscle, as well as other anatomical features,which could potentially squeeze or pinch the support member inwardly andcause undesirable buckling and/or bunching of the implanted patch.

The support member may include first and second ends that are spacedapart to form an interruption. In this manner, a slit, such as a keyholearrangement, may be readily formed in the repair fabric through theinterruption and into an interior region of the body portion. The slitand/or keyhole may be configured to receive a body structure, includinga cord structure such as the spermatic cord. It is to be understood,however, that the support member may be configured to completelysurround the body portion and not include an interruption.

For a procedure that may involve receiving a body structure, such as aspermatic cord, through an interruption and the repair fabric, thesupport member may be configured with segments extending along thetransition region that are spaced apart a sufficient amount toaccommodate the body structure therebetween. In one embodiment, thesegments of the support member may have an inner width therebetween thatpermits the body structure to be received along the transition region.

The prosthesis may have a non-circular shape, such as a generally oval,elliptical or egg shape, which is suitable for mending a groin hernia.The prosthesis may be shaped so as to have a major axis and a minoraxis. The support member may include a relatively narrow transitionsegment, formed at least in part by indentations or notches that areoffset to one side of the minor axis toward a lateral end of theprosthesis, for inhibiting potential squeezing or pinching of thesupport member when implanting the patch through an opening in thetissue and/or muscle, such as the transversalis fascia, separating thetissue planes. The support member may include an interruption located onthe major axis at the lateral end of the patch. The prosthesis may begenerally symmetric about its major axis and generally asymmetric aboutits minor axis.

The support member may be rollable, foldable or otherwise collapsible,when the repair fabric is reduced in size for delivery to the repairsite, and may spring back, either automatically or upon the influence ofa force (e.g., body heat where the support is formed of a shape memorymaterial, such as NITINOL) to its initial expanded shape on deploymentat the repair site, influencing the prosthesis to assume its unfurled orspread out configuration.

The support member may be formed of a monofilament that has beenpreformed into the desired shape. The support member may be comprised ofa resorbable or a non-resorbable material. In one embodiment, thesupport member is formed of a resorbable material to provide short-termsupport along an implanted patch. A resorbable support member alsoeliminates potential long-term sensation that could otherwise beexperienced by a patient from use of the support member.

The prosthesis may include one or more positioning tethers, such asstraps, to facilitate placement and fixation of the patch. A tether maybe positioned on the patch in an off-center location. The center of thetether may be offset from the center of the patch in a direction towardthe lateral end of the patch along the major axis. Such an arrangementmay be particularly suited for a preperitoneal inguinal hernia repairperformed though an open, anterior approach. The tether may beconfigured with a length that is sufficient to be accessible fromoutside a patient to facilitate placement, positioning and fixation ofthe patch.

The repair fabric may be formed of a tissue infiltratable material, suchas a knit fabric, or may be composed of a solid or substantiallynon-porous material. The repair fabric may be formed of one or morelayers of the same or dissimilar material. The repair fabric may beformed with portions that are tissue infiltratable and other portionsthat are non-tissue infiltratable, providing selected areas of therepair device with different tissue ingrowth and adhesion resistantproperties. The repair fabric may be formed of permanent or resorbablematerial.

FIGS. 1-2 illustrate one embodiment of a prosthesis 20 for mending softtissue and muscle wall defects, such as a groin defect.

The prosthesis 20 includes a repair fabric of implantable, biologicallycompatible material with a body portion 22 that is configured to bepositioned in one or more tissue planes to mend the defect. As shown,the prosthesis is configured as a patch that includes a medial portion24 and a lateral portion 26 which are positionable in the same tissueplane or different tissue planes that are separated from each other bytissue and/or muscle. The patch also includes a transition region 28which is configured to pass through the tissue and/or muscle separatingthe tissue planes when the prosthesis is employed for a multi-planeprocedure. In one embodiment, the transition region extends along thelateral portion of the patch. The transition region may also extendalong the medial portion of the patch. Alternatively or additionally,the transition region may extend along a portion of the patch betweenthe medial and lateral portions.

The prosthesis may be configured with any desired characteristic orcombination of characteristics including, but not limited to, strength,stiffness, flexibility, tissue integration and/or adhesion resistance,suitable for the repair as should be apparent to one of skill. Althoughthe prosthesis is described in connection with a patch-type embodiment,the prosthesis may include a plug, a combination plug and patch, andother suitable arrangements for mending the defect.

To help deploy the patch into a spread out configuration for mending adefect, it may be desirable to employ a patch that is sufficiently rigidso that it can be easily and effectively manipulated and positioned in adesired anatomical region, yet sufficiently flexible so that the patchmay be adequately handled by the physician implanting the patch andtolerated by the patient receiving the patch. A desired stiffness,flexibility or compliance may be provided to the patch using suitablecomponents, features, materials, coatings and/or treatments as shouldapparent to one of skill in the art.

In one illustrative embodiment as shown in FIGS. 1-2, to balance thestiffness and flexibility characteristics, the prosthesis 20 includes asupport member 30 to reinforce portions of the patch and to help deployand/or hold the patch in a spread out configuration. The support member30 may be coupled to the patch in any suitable manner, as the presentinvention is not limited in this respect. Suitable attachment methodsinclude, but are not limited to, stitching, bonding, adhesive, andintegral formation with the repair fabric of the patch, as should beapparent to one of skill.

The support member 30 contributes to the stability of the patch,allowing it to deploy into and remain in a desired shape. For example,the support member may aid in returning the patch to a substantiallyunfurled or spread out configuration after the folded up or otherwisereduced prosthesis has been delivered to the repair site through eitheran open incision or a cannula. This stability facilitates deployment andplacement of the patch by making it easy to handle. Also, this stabilityminimizes the tendency of the patch to fold, bend, or otherwise bedislocated.

In one embodiment, the support member 30 includes a substantiallycontinuous loop or ring positioned adjacent the outer margin of thepatch. In the illustrative embodiment, the support member 30 is spacedinwardly from the outer peripheral edge 32 of the repair fabric.However, it should be appreciated that the present invention is notlimited in this respect, as the support member 30 may be disposed at theperipheral edge and/or at discrete locations throughout the body of thepatch.

The support member 30 may be configured to substantially surround thebody portion so as to help deploy and/or hold the body portion 22 in thespread out configuration for covering the defect. The support member 30may have a resiliency that allows the support member to deform from aninitial shape and then return to the initial shape to return the bodyportion to the spread out configuration.

In certain repair procedures, it may be desirable to configure thesupport member in a manner that inhibits the application of undesirableforces between the support member and adjacent anatomy at the repairsite. In one embodiment, the support member may be configured so as toinhibit inwardly directed deflection by the adjacent anatomy. Forexample, pinching or squeezing the support member inwardly couldpotentially cause buckling and/or bunching of the repair fabric whichcould adversely impact repair of the defect with the prosthesis.

In one illustrative embodiment shown in FIGS. 1-2, the support member 30may be configured with a transition segment 34 along the transitionregion of the patch that permits the patch to be positioned within anincision or dissected tissue and/or muscle without causing the supportmember to be deflected or squeezed inwardly by adjacent anatomy. Thetransition segment 34 may be configured with an outer width W₁ that doesnot exceed the size of the incision, dissection or other opening createdor otherwise present through the tissue and/or muscle separating thetissue planes. The transition segment may extend along a region of thepatch located from a first distance X₁ to a second distance X₂ relativeto the lateral end of the patch.

In one embodiment, the outer width W₁ of the transition segment of thesupport member does not exceed 4.2 cm along a region X₁-X₂ of the patchlocated approximately 1 inch (2.5 cm) (X₁) to approximately 2 inches(5.1 cm) (X₂) from the lateral end 36 of the patch. The outer width W₁of the transition segment along the region X₁-X₂ may range from 2.5 cmto 4 cm. In another embodiment, the outer width W₁ of the transitionsegment of the support member does not exceed 3.7 cm along a region ofthe patch located approximately 1 inch (2.5 cm) (X₁) to approximately1.5 inches (3.8 cm) (X₃) from the lateral end 36 of the patch. The outerwidth W₁ of the transition segment of the support member may range from2.5 cm to 3.5 cm along the region X₁-X₃ of the patch. A patch includinga support member with a transition segment configured in this manner maybe particularly suited for mending a groin hernia using the ONSTEPprocedure. However, it is to be appreciated that the support member maybe provided with a transition segment having other configurationssuitable for other procedures as should be apparent to one of skill.

As shown, the support member 30 may deviate inwardly away from the outerperiphery 32 of the patch to form a pair of indentations or notches 38.The support member 30 may have a generally convex curvature as itextends about the medial portion 24 while the indentations 38 may have agenerally concave curvature extending from the medial portion 24 alongthe transition region 28 toward the lateral portion 26. As illustrated,segments of the support member extending from the indentations towardthe lateral end of the patch may have a generally convex curvature. Aportion of the support member along the lateral portion of the patch maybe narrower than the transition segment, and a portion of the supportmember along the medial portion of the patch may be wider than thetransition segment.

In the illustrative embodiment shown in FIG. 1, segments of repairfabric may occupy the regions of the patch at the indentations 38between the support member 30 and the outer periphery 32. For example,the fabric segments 40 may enhance tissue ingrowth about the portion ofthe patch, such as the transition region, extending through tissueand/or muscle separating tissue planes involved with the defect repair.If desired, the fabric segments may be trimmed to accommodate theparticular anatomy.

As illustrated in FIGS. 1-2, the support member 30 may include first andsecond ends 42, 44 that are spaced apart to form an interruption 46 inthe support member at an end of the prosthesis. In this manner, a slitand/or keyhole arrangement may be formed in the repair fabric at theinterruption 46 and into an interior region of the body portion 22without having to cut through the support member. The slit and/oropening may be configured to receive a body structure, including a cordstructure such as the spermatic cord. It is to be understood, however,that the support member in some embodiments may be configured tocompletely surround the body portion and not include an interruption.

For a procedure that may involve receiving a body structure, such as aspermatic cord, through an interruption and the repair fabric, thesupport member 30 may be configured with transition segments 34extending along the transition region that are spaced apart a sufficientamount to accommodate the body structure therebetween. For example, thesegments 34 of the support member may have a minimum width W₂therebetween that permits the body structure to be received along thetransition region. In one embodiment, the support member may have aminimum width W₂ of about 2.4 cm for receiving a spermatic cordtherebetween, such as when mending a groin hernia, although otherconfigurations may be implemented as should be apparent to one of skill.

The support member 30 may be integrated with the patch in any suitablemanner as the present invention is not limited in this respect. In oneembodiment, as shown in FIGS. 1-2, the support member 30 is sandwichedbetween first and second layers 50, 52 of repair fabric and may or maynot be physically attached thereto. The support member 30 may be heldwithin a channel 54 between the first and second layers. In theillustrative embodiment, the channel 54 is formed by a pair of seams 56,58 that join the first and second layers and follow the contour of thesupport member 30. The seams may be formed by a series of stitches, orother suitable arrangements, extending along the outside and inside edgeof the support member 30 to keep it from moving with respect to thefirst and second layers. In some embodiments, one seam extending alongone side of the support member may be sufficient.

It should be appreciated that the invention is not limited to anyparticular attachment method, as the first and second layers 50, 52 maybe attached along the seams 56, 58 or other desired locations usingother suitable techniques. For example, the layers may be bondedtogether by melting the layers at specific locations or in a specificpattern; sonic, induction, vibration, or infrared/laser welding thelayers; or using a suitable bonding agent. The point or points ofattachment may comprise any suitable pattern as would be apparent to oneof skill in the art.

In one embodiment as shown in FIG. 2, the support member may besurrounded by a containment sleeve 60 that is located between the firstand second layers. A containment sleeve may be particularly advantageouswhen used in conjunction with a resorbable support member. The sleevemay be formed from a mesh fabric that includes interstices or pores thatallow tissue infiltration or ingrowth that eventually surrounds andresorbs the support member 30. However, it should be understood that acontainment sleeve is not required for each embodiment of the invention,including embodiments that employ a resorbable support member.

In one illustrative embodiment shown in FIGS. 1-2, the first layer 50may be configured as a full layer of fabric material that is sized andshaped to cover the defect. The second layer 52 may have a generallyannular configuration that overlies and generally follows the contour ofthe support member to reduce the overall amount of material for theprosthesis. However, it is to be appreciated that the second layer 52may have any suitable configuration as should be apparent to tone ofskill in the art.

For some repair procedures, it may be desirable to provide one or morepockets that may aid in deploying and/or positioning of the prosthesisduring implantation as should be understood by one of skill in the art.The pocket may be configured to receive a sufficient length of one ormore fingers of an individual's hand (or a suitable surgical instrument)for deploying and/or placing the prosthesis.

In one embodiment shown in FIGS. 1-2, the prosthesis may include apocket 62 located at an end of the medial portion of the patch. Thepocket 62 may be created with a layer 64 of fabric that is attached tothe body portion in a manner that forms the pocket therebetween. Asshown in FIG. 2, the pocket layer 64 may be attached to the body portionalong a seam 65, such as a stitch line, that is located outside thesupport member 30 and adjacent the outer periphery of the of the patch.This arrangement may facilitate placement of the patch by providing apocket that extends close to the edge of the patch which may allow auser to more readily recognize the position of the outer edge throughtactile feedback during implantation. An opening may be provided forpermitting access of an individual's fingers (or surgical instrument)therethrough and into the pocket. The opening may be located along anedge 66 of the layer of fabric. However, the pocket may employ anysuitable configuration and/or may be located at any suitable portion ofthe prosthesis as should be apparent to one of skill in the art. Ifdesired, one or more additional pockets, such as a pocket located at thelateral portion 26, may be provided on the prosthesis.

As indicated above, the patch may be configured with a desired level ofstiffness, flexibility or compliance in one or more regions that helpsdeploy and/or hold the body portion in an open or spread outconfiguration for mending the defect, facilitates manipulating the bodyportion and/or permits the prosthesis to be flexed and implanted indifferent tissue planes while minimizing patient sensation from theimplanted prosthesis.

In one embodiment, the lateral portion 26 of the patch may be configuredwith a level of stiffness that facilitates implantation of the patch indifferent tissue planes while inhibiting patient sensation to theimplanted patch. For purposes of this application, the stiffness of thelateral portion is determined following the test procedure describedbelow using the test fixture illustrated in FIG. 6. In one embodiment,the patch may be configured with a lateral portion that has a stiffnessof 0.04 psi to 0.09 psi. In another embodiment, the lateral portion mayhave a stiffness of 0.04 psi to 0.07 psi. In another embodiment, thelateral portion may have a stiffness of 0.04 psi to 0.06 psi. In anotherembodiment, the lateral portion may have a stiffness of 0.05 psi to 0.09psi. In another embodiment, the lateral portion may have a stiffness of0.05 psi to 0.07 psi. It is to be appreciated, however, that the patchmay be configured with the lateral portion or other portions havingother stiffnesses as should be apparent to one of skill.

The prosthesis may be configured to have any suitable shape or size thatis conducive to facilitate mending of a particular defect, such as agroin hernia. In the embodiments shown in FIGS. 1-2, the patch has arelatively flat configuration. However, the patch need not be flat, andconvex, concave, convex/concave, and more complex three-dimensionalshapes also are contemplated. The patch may be sufficiently pliable tofacilitate manipulation and/or reduction of the patch during delivery tothe defect and/or to conform the patch to the anatomical site ofinterest.

In the illustrative embodiments shown in FIGS. 1-2, the prosthesis has agenerally oval, elliptical or egg shape suitable for mending a groinhernia in the inguinal canal. The geometry of the prosthesis 20 isgenerally oval with a major axis 70 extending along the longest portionof the prosthesis and a minor axis 72 extending across the widestportion of the prosthesis in a direction perpendicular to the majoraxis. As illustrated in FIG. 1, the prosthesis is substantiallysymmetric about the major axis 70 and is substantially asymmetric aboutthe minor axis 72 providing a generally ovoid shape (e.g., egg shape)with a narrower lateral portion 26, a wider medial portion 24, andopposing sides 74, 76 that converge towards each other in a directionfrom the medial portion 24 toward the lateral portion 26. It is to beappreciated that the prosthesis may be configured with any suitableshape, such as a shape that is symmetric about both axes, asymmetricabout both axes, or asymmetric about the major axis and symmetric aboutthe minor axis. Examples of other shapes include, but are not limitedto, circular, square, rectangular, and irregular configurations. Therepair fabric may be sized to cover part or, preferably, all of thedefect.

The medial portion 24 has a rounded configuration that generallyconforms to the shape of the repair site, for example, a preperitonealspace, such as the space of Retzius. The medial portion of theprosthesis has a relatively larger configuration or size to provide morepotential coverage at the defect site. The lateral portion 26 of theprosthesis may have a smaller, less rounded configuration relative tothe medial portion which may be conducive for positioning in a separatetissue plane, such as an onlay position, for example, between anexternal oblique aponeurosis and an internal oblique aponeurosis.However, it is to be understood that the medial and lateral portions mayhave any suitable configurations apparent to one of skill in the art.

The transition region 28 and the interruption 46 may be positioned inany desirable location, relative to the body portion 22, which issuitable for a particular repair. In the illustrative embodiment, thetransition region 28 is offset from the minor axis 72 toward the lateralportion 26 of the prosthesis. The interruption 46 is centrally locatedalong the major axis 70 at the lateral portion 26 of the prosthesis. Asshown, the transition region 28 may be located entirely to one side ofthe minor axis toward the lateral portion. The illustrated embodimentsof the interruption and the transition region are particularly suitedfor mending a groin hernia. However, it is to be appreciated that theprosthesis is not so limited and the locations of the interruptionand/or the transition region may be varied for other repairs as would beapparent to one of skill in the art.

For certain procedures, it may be desirable to employ one or morepositioning tethers to facilitate placement and fixation of the patch.In one illustrative embodiment shown in FIGS. 3-4, the prosthesis mayinclude a patch 20 and a tether 80, such as a strap, extending from thepatch. In this embodiment, the patch generally corresponds to theembodiment described above with reference to FIGS. 1-2, such thatdetails of the patch will not be described in connection with thisembodiment. However, the prosthesis may include a pocket 62 a, 62 b atboth the medial and lateral portions of the patch. As illustrated, thepocket layer 64 may be configured to form the pockets in conjunctionwith the body portion of the patch.

In one embodiment, the tether 80 may be positioned on the patch in anoff-center location. As shown, the center 82 of the tether 80 may beoffset from the center 84 of the patch in a direction toward the lateralend of the patch along the major axis. The off-center location of thetether allows the patch to be fixated through either an indirect herniaor a direct hernia while still providing desired coverage of the defectspaces. Such an arrangement may be particularly suited for apreperitoneal inguinal hernia repair performed through an open, anteriorapproach. The tether may be configured with a length that is sufficientto be accessible from outside a patient to facilitate placement,positioning and fixation of the patch.

The tether 80 may include a base 86 that is secured, such as bystitching, to the patch. As shown, the base 86 may be located betweenthe second layer 52 and a pocket layer 64, if provided. In oneembodiment, the tether includes a pair of straps 80 a, 80 b that extendfrom the base and are joined together with a looped end 88. The base mayinclude separate bases at the end of each strap. It is to beappreciated, however, that other arrangements are contemplated as shouldbe apparent to one of skill.

In one embodiment, the tether may be formed from a repair fabric, suchas a mesh fabric similar to material employed for other layers of thepatch. The tether may have a width of approximately 0.5 inches and alength of approximately 3.8 inches. The tether may be offset from thecenter of the patch toward the lateral end by a distance X₄ of 0.25inches. However, the strap may be formed of any suitable material, haveany suitable configuration and be located in any suitable position asshould be apparent to one of skill.

In one embodiment for a mending a groin hernia, the patch 20 has alength along the major axis 60 of approximately 5.6 inches and a widthalong the minor axis 62 of approximately 3.4 inches. In anotherembodiment for mending a groin hernia, the patch 20 has a length alongthe major axis 60 of approximately 6.2 inches and a width along theminor axis 62 of approximately 4.0 inches. Each patch may employ asupport member having a transition segment with a configuration asdescribed above. The interruption may have a width from approximately0.5 cm to approximately 4.0 cm. However, it is to be understood thatthese dimensions are merely exemplary and that the prosthesis may beconfigured to have any suitable size and interruption width as would beapparent to one of skill for a particular repair.

The repair fabric may include at least one layer of tissue infiltratablematerial that permits or is otherwise susceptible to tissue or muscleingrowth to enhance the repair of the defect. In one embodiment, eachlayer 50, 52, 64 is formed of a biologically compatible, flexible repairmaterial that includes a plurality of interstices or openings whichallow sufficient tissue or muscle ingrowth to integrate the prosthesiswith host tissue or muscle after implantation. Multiple layers of tissueinfiltratable fabric may enhance the strength of the patch and/or theamount of tissue ingrowth to the patch. However, the invention is notlimited in this respect, and any one or each layer may be formed of anybiologically compatible material, suitable for repairing a tissue ormuscle wall defect as would be apparent to one of skill.

In one embodiment, the layers 50, 52, 64 of the prosthesis 20 are eachformed from a sheet of knitted polypropylene monofilament mesh fabrichaving a thickness of approximately 0.016 inches and knitted frompolypropylene monofilament having a diameter of approximately 0.0043inches. The tether 80, if employed, may be formed of similar meshfabric.

When implanted, the polypropylene mesh promotes rapid tissue or muscleingrowth into and around the mesh structure. Alternatively, othersurgical materials which are suitable for tissue or muscle reinforcementand defect correction may be utilized including BARD MESH (availablefrom C.R. Bard, Inc.), SOFT TISSUE PATCH (microporous ePTFE—availablefrom W.L. Gore & Associates, Inc.); SURGIPRO (available from USSurgical, Inc.); TRELEX (available from Meadox Medical); PROLENE andMERSILENE (available from Ethicon, Inc.); and other mesh materials(e.g., available from Atrium Medical Corporation). Resorbable materials,including polyglactin (VICRYL—available from Ethicon, Inc.) andpolyglycolic acid (DEXON—available from US Surgical, Inc.), may besuitable for applications involving temporary correction of tissue ormuscle defects. Collagen materials such as COOK SURGISIS, available fromCook Biomedical, Inc. may also be used. It also is contemplated that themesh fabric may be formed from multifilament yarns and that any suitablemethod, such as knitting, weaving, braiding, molding and the like, maybe employed to form the mesh material.

In one embodiment, the support member may be formed from a length of0.038 inch diameter resorbable polydioxanone (PDO) monofilament. In thismanner, the support member provides a desired level of support forinitial placement and positioning of the prosthesis. However, it shouldbe appreciated that the invention is not limited in this respect andthat the support member may be made of any suitable resorbable andnon-resorbable material including, but not limited to, a resorbablePLA/PCL blend or non-resorbable materials, such as polyethyleneterephthalate (PET) nylon, polypropylene, and polyester, and having anysuitable diameter or cross-section. If desired, the stiffness orrigidity of the support member may be varied depending on the size ofthe patch. For example, the cross-sectional diameter and/or the springconstant of the material of the monofilament may be varied in a mannerto provide a desired stiffness throughout or in one or more portions ofthe prosthesis.

In certain embodiments, the prosthesis may include an adhesion resistantbarrier overlying at least a portion, and preferably all, of one side ofthe ingrowth layer and/or an edge barrier to isolate one or more edgesof the patch from adjacent tissue, muscle or organs. The barrier layerand/or edge barrier may be formed of a material and/or with a structurethat does not substantially stimulate and, in certain embodiments, mayresist tissue, muscle or organ ingrowth and adhesion formation whenimplanted, thereby reducing the incidence of undesired postoperativeadhesions between the ingrowth layer and adjacent tissue, muscle ororgans. If desired, such a barrier layer and/or edge barrier may beformed from any suitable material or structure apparent to one of skillin the art, including, but not limited to, a sheet of expandedpolytetrafluoroethylene (ePTFE) having a microporous pore structure thatinhibits tissue ingrowth.

In certain embodiments, the prosthesis may be loaded with one or moremedicinal or therapeutic agents including, but not limited to, ananalgesic or antibiotic.

As indicated above, the prosthesis 20 illustrated in FIGS. 1-2 may beparticularly suited for mending a groin hernia using the ONSTEPprocedure. As illustrated in FIG. 5, the procedure involves creating aspace between the external oblique aponeurosis 100 and the internaloblique aponeurosis 102 superiorly and laterally to an incision site.This space may be configured to receive a lateral portion of aprosthetic repair patch. Medially and inferiorly of the dissected spacebetween the two oblique aponeuroses, and remote from the groin defect,the transversalis fascia 104 is penetrated to reach the space of Retzius106—an area located deep of the pubic bone 110 and anteriorly of theperitoneum 112. A surgically created pathway now runs from the space ofRetzius 106, a preperitoneal space, to the dissected area between theexternal oblique aponeurosis 100 and the internal oblique aponeurosis102.

A patch 20 is implanted along this pathway, with the lateral portion 26positioned in the dissected space between the external obliqueaponeurosis and the internal oblique aponeurosis and the medial portion24 extending through the transversalis fascia to the preperitoneal areaof the pubic bone 110. A transition region 28 runs with the spermaticcord 114, extending transversely between the medial and lateral portionsof the prosthetic repair patch. A slit may be provided in the lateralportion to define two separable portions, referred to as “tails”, whichmay be spread apart to accommodate the spermatic cord. Subsequently, thetails are reunited and, if desired, sutured together or otherwisesecured.

Examples

The following examples are illustrative only and are not intended tolimit the scope of the present invention.

The stiffness of an implantable prosthesis, similar to the patchillustrated in FIGS. 1-2, was tested and the resulting data is presentedin Table 1 below. More particularly, the stiffness was tested for thelateral portion of the patch. For a groin hernia repair, such as usingthe ONSTEP procedure, the lateral portion may be implanted anteriorly tothe transversalis fascia in an onlay position.

FIG. 6 provides a schematic illustration of a test fixture 200 fortesting stiffness of the prosthesis. An Instron tester 202 with a flatplate test probe 204 (measuring 2″×3″) is used to determine thestiffness of the samples. The tester measures the force exerted by thepatch against the probe to bend the lateral portion of the sampleapproximately 90°.

The medial portion 24 of the sample, approximately 3 to 3.6 inchesdepending on the size of the patch, is placed between a base plate 206and a foam pad 208 which is secured to the base. Approximately 2 inchesof the patch, corresponding to the lateral portion 26, extends from aslit 210 in the foam pad and is positioned below the test probe 204extending generally in a direction along the horizontal plane of thepad. In this manner, the medial and lateral portions of the patch areplaced in two different planes.

The test probe 204 is advanced in the downward vertical direction at arate of 1 inch/min to deflect the lateral portion 26 of the patchdownward toward the pad 208. The test probe 204 is advanced to aposition approximately 0.13 inches above the foam pad. Peak forceexerted by the patch against the probe was recorded.

Eighteen samples were tested, including 10 samples (N) of a medium patch(5.6″×3.4″) and 8 samples (N) of a large patch (6.2″×4.0″). The lateralportions of the medium and large samples generally had the sameconfigurations with a test area of about 4.55 in² (medium) and 4.56 in²(large). The average stiffness was calculated for the lateral portion.Stiffness data is provided in Table 1, measured in lbf/in² (psi).

TABLE 1 Medium Patch Large Patch Mean (psi) 0.050 0.070 Std. Dev. 0.0070.010 N (Tested Samples) 10 8 Max. (psi) 0.062 0.091 Min. (psi) 0.0410.057

It should be understood that the foregoing description of variousembodiments of the invention are intended merely to be illustrativethereof and that other embodiments, modifications, and equivalents ofthe invention are within the scope of the invention recited in theclaims appended hereto.

What is claimed is:
 1. An implantable prosthesis for mending a groinhernia, the implantable prosthesis comprising: a patch of repair fabricincluding a medial portion, a lateral portion, a lateral end and atransition region, the medial portion configured to be positioned at afirst tissue plane, the lateral portion configured to be positioned at asecond tissue plane offset from the first tissue plane, the transitionregion configured to be positioned through an opening in tissue and/ormuscle separating the first and second tissue planes; and a supportmember located along the medial portion, the lateral portion and thetransition region to help deploy and/or hold the patch in a spread outconfiguration, the support member including a transition segmentassociated with the transition region of the patch, the transitionsegment being located from at least 2.5 cm to at least 5.1 cm from thelateral end of the patch and having an outer width that does not exceed4.2 cm.
 2. The implantable prosthesis according to claim 1, wherein thetransition segment of the support member has an outer width of 2.5 cm to4.0 cm.
 3. The implantable prosthesis according to claim 1, wherein aportion of the transition segment located at least 2.5 cm to at least3.8 cm from the lateral end of the patch has an outer width that doesnot exceed 3.7 cm.
 4. The implantable prosthesis according to claim 3,wherein the portion of the transition segment of the support member hasan outer width of 2.5 cm to 3.5 cm.
 5. The implantable prosthesisaccording to claim 1, wherein the transition region extends in alongitudinal direction along the patch, the transition segment of thesupport member having a length of 2.5 cm in the longitudinal direction.6. The implantable prosthesis according to claim 1, wherein thetransition segment extends 2.5 cm to 5.1 cm from the lateral end of thepatch.
 7. The implantable prosthesis according to claim 6, wherein thelateral portion has a stiffness of 0.04 psi to 0.09 psi.
 8. Theimplantable prosthesis according to claim 6, wherein the lateral portionhas a stiffness of 0.04 psi to 0.07 psi.
 9. The implantable prosthesisaccording to claim 1, wherein the transition segment corresponds to thetransition region of the patch.
 10. The implantable prosthesis accordingto claim 1, wherein the support member substantially surrounds the patch11. The implantable prosthesis according to claim 10, wherein thesupport member includes a convex segment along a substantial portionthereof and pair of concave segments, the convex segment extending alongthe medial portion and the concave segments extending along at least aportion of the transition region.
 12. The implantable prosthesisaccording to claim 11, wherein the support member includes first andsecond ends that are spaced apart to form an interruption therebetween.13. The implantable prosthesis according to claim 12, wherein the patchhas an oval configuration with a major axis and a minor axis.
 14. Theimplantable prosthesis according to claim 13, wherein the patch includesa lateral end, the interruption being located at the lateral end on themajor axis.
 15. The implantable prosthesis according to claim 14,wherein the concave segments are located between the minor axis and thelateral end.
 16. The implantable prosthesis according to claim 13,wherein the medial portion is wider than the lateral portion.
 17. Theimplantable prosthesis according to claim 1, wherein a portion of thesupport member along the medial portion has an outer width that islarger than the transition segment of the support member.
 18. Theimplantable prosthesis according to claim 17, wherein a portion of thesupport member along the lateral portion has an outer width that issmaller than the transition segment of the support member.
 19. Animplantable prosthesis for mending a groin hernia, the implantableprosthesis comprising: a patch of repair fabric including a medialportion and a lateral portion, the medial portion configured to bepositioned at a first tissue plane, the lateral portion configured to bepositioned at a second tissue plane offset from the first tissue planeand separated by tissue and/or muscle, the lateral portion having astiffness of 0.04 psi to 0.09 psi.
 20. The implantable prosthesisaccording to claim 19, wherein the lateral portion has a stiffness of0.04 psi to 0.07 psi.
 21. The implantable prosthesis according to claim19, wherein the patch includes a transition region that is configured toextend through the tissue and/or muscle separating the first and secondtissue planes.
 22. The implantable prosthesis according to claim 21,further comprising a support 25 member located along the medial portion,the lateral portion and the transition region to help deploy and/or holdthe patch in a spread out configuration.
 23. The implantable prosthesisaccording to claim 22, wherein the support member includes a transitionsegment extending along a portion of the patch associated with thetransition region, the transition segment having an outer width of 2.5cm to 4.0 cm.
 24. The implantable prosthesis according to claim 23,wherein the transition segment of the support member has an outer widthof 2.5 cm to 3.5 cm.
 25. The implantable prosthesis according to claim23, wherein the transition region extends in a longitudinal directionalong the patch, the transition segment of the support member having alength of 2.5 cm in the longitudinal direction.
 26. The implantableprosthesis according to claim 23, wherein the patch includes a lateralend, the transition segment of the support member being located at least2.5 cm from the lateral end of the patch.
 27. The implantable prosthesisaccording to claim 26, wherein the transition segment extends 2.5 cm to5.1 cm from the lateral end of the patch.
 28. The implantable prosthesisaccording to claim 27, wherein the transition segment corresponds to thetransition region of the patch.
 29. The implantable prosthesis accordingto claim 27, wherein the support member substantially surrounds thepatch
 30. The implantable prosthesis according to claim 29, wherein thesupport member includes a convex segment along a substantial portionthereof and pair of concave segments, the convex segment extending alongthe medial portion and the concave segments extending along at least aportion of the transition region.
 31. The implantable prosthesisaccording to claim 30, wherein the support member includes first andsecond ends that are spaced apart to form an interruption therebetween.32. The implantable prosthesis according to claim 31, wherein the patchhas an oval configuration with a major axis and a minor axis.
 33. Theimplantable prosthesis according to claim 32, wherein the patch includesa lateral end, the interruption being located at the lateral end on themajor axis.
 34. The implantable prosthesis according to claim 33,wherein the concave segments are located between the minor axis and thelateral end.
 35. The implantable prosthesis according to claim 32,wherein the medial portion is wider than the lateral portion.
 36. Amethod of mending a groin hernia, the method comprising acts of: (a)providing an implantable prosthesis that includes a patch of repairfabric and a support member to help deploy and/or hold the patch in aspread out configuration, the patch including a medial portion, alateral portion and a transition region, the support member beinglocated along the medial portion, the lateral portion and the transitionregion, the support member including a transition segment associatedwith the transition region; and (b) implanting the prosthesis to mendthe groin hernia by: (i) positioning the medial portion of the patch ata first tissue plane; (ii) positioning the lateral portion of the patchat a second tissue plane offset from the first tissue plane; and (iii)positioning the transition region of the patch through an opening intissue and/or muscle separating the first and second tissue planes, thetransition segment of the support member having an outer width that doesnot exceed a corresponding dimension of the opening.
 37. The methodaccording to claim 36, wherein act (a) includes providing a prosthesiswith the transition segment of the support member having an outer widththat does not exceed 4.2 cm.
 38. The method according to claim 37,wherein act (a) includes providing a prosthesis with the transitionsegment of the support member extending 2.5 cm to 5.1 cm from thelateral end of the patch.
 39. The method according to claim 37, whereinact (a) includes providing a prosthesis with the transition segment ofthe support member having an outer width of 2.5 cm to 4.0 cm.
 40. Themethod according to claim 39, wherein act (a) includes providing aprosthesis with the transition segment of the support member having anouter width of 2.5 cm to 3.5 cm.
 41. The method according to claim 39,wherein the transition region extends in a longitudinal direction alongthe patch, act (a) includes providing a prosthesis with the transitionsegment of the support member having a length of 2.5 cm in thelongitudinal direction.
 42. The method according to claim 39, whereinthe patch includes a lateral end, act (a) includes providing aprosthesis with the transition segment of the support member located atleast 2.5 cm from the lateral end of the patch.
 43. The method accordingto claim 39, wherein act (a) includes providing a prosthesis with thelateral portion having a stiffness of 0.04 psi to 0.09 psi.
 44. Themethod according to claim 39, wherein act (a) includes providing aprosthesis with the lateral portion having a stiffness of 0.04 psi to0.07 psi.
 45. The method according to claim 39, wherein act (b)(i)includes positioning the medial portion in a preperitoneal space. 46.The method according to claim 45, wherein act (b)(i) includespositioning the medial portion in the space of Retzius.
 47. The methodaccording to claim 45, wherein act (b)(ii) includes positioning thelateral portion between an external oblique aponeurosis and an internaloblique aponeurosis.
 48. The method according to claim 47, wherein act(b)(iii) includes positioning the transition segment of the supportmember through an opening in the transversalis fascia.